overview of septic systems - charlotte county, florida · 2019-01-31 · septic system will have to...

Overview of Septic Systems

Joseph D. Pepe, Ed. D. MSAFlorida Department of Health

Charlotte County

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Topic: Overview of Septic Systems in Florida• Review Onsite Sewage Treatment and Disposal Systems in Charlotte

County• Understand basic functioning of septic systems• Review proper maintenance of septic systems• Understand options for higher level of treatment (aerobic treatment units

and performance-based treatment systems)• Introduce Springs Protection Basin Management Action Plans (BMAP) as an

example of stricter requirements

Objectives

Presenter

Presentation Notes

- Great resources found within community and promotion of real-time events that central office would not have been able to facilitate (ie Pinellas coverage of Zika meeting with Governor & Hurricane Matthew emergency messaging and awareness from Duval) - Good local interaction with partners and leveraging those relationships in order to cross promote health events - Some posts that were well-written and available for retweeting on central office account (Flu shot clinics, Heart Day events, Hurricane Matthew updates, etc)

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• Onsite Sewage Treatment and Disposal Systems (OSTDS)• Are individual wastewater treatment systems where sewer is not available• Are permitted by the Florida Department of Health in Charlotte County• Usually, are a septic system consisting of septic tank and drainfield• Can include treatment types other than conventional systems:

• Aerobic Treatment Units and Performance Based Treatment System

Terminology

Presenter

Presentation Notes

- Great resources found within community and promotion of real-time events that central office would not have been able to facilitate (ie Pinellas coverage of Zika meeting with Governor & Hurricane Matthew emergency messaging and awareness from Duval) - Good local interaction with partners and leveraging those relationships in order to cross promote health events - Some posts that were well-written and available for retweeting on central office account (Flu shot clinics, Heart Day events, Hurricane Matthew updates, etc)

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Systems in Charlotte County

Presenter

Presentation Notes

Septic: 12,266 Known; 25,644 Likely (About 37,910 Septic) Green and Light Green Sewer: 51,057 Known; 4,933 Likely (About 55,990 Sewer) Brown and Orange Have no data on 6,544 parcels. Grey

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Searchable Web Application

h t t p s : / / g i s . f l h e a l t h . g o v / F L W M I

https://gis.flhealth.gov/FLWMI

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Septic Tank and Drainfield(A Septic System)

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Septic Tank

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Sedimentation in scum & sludge layers

Digestion of solids without oxygen

Storage of scum and sludge

Clarified effluent from clear zone flows to the drainfield.

Functions of a Septic Tank

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coffee groundscooking fats & greasewet strength towelsdisposable diaperscigarette buttsplasticskitty litter

Indigestible Materials to Avoid

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Conventional Septic System

The Old Way:Pipe and Gravel

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The Drainfield (Treatment and Disposal)

2 feet between bottom of drainfield and seasonal high water table now required to provide air and soil treatment

6” minimum between top of drainfield and ground surface required

thickness of drainfield (12” for gravel)

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The Drainfield (Treatment and Disposal)

Most pollutants other than nitrate are treated in drainfield

NO3

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Mound as Alternative Drainfield

•Mound system is a septic system alternative that allows separation of drainfield from groundwater or rock

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Septic Tank and Drainfield(A Septic System)

• Modern conventional septic and drainfield systems are effective at removing organic carbon, suspended solids, and bacteria

• However, these systems are not designed to effectively remove nitrogen

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How to take care of your system?1. Know where it is2. Three P’s

• Pump/inspect for accumulation of sludge • Protect outside (never drive on it; direct

rainfall away)• Prevent malfunction inside (flush only human

waste, no toxics, fix leaky toilets)

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“Advanced” OSTDS

advanced septic systemsperformance-based septic tanks

enhanced systems

more efficient septic tanks

improved septic tanks

souped-up septics

more-advanced septic system nitrogen-reducing septic systems

performance-based septic systems

advanced aerobic systems

high-performance septic systems

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In-Ground Nitrogen Reducing Biofilter

• A nitrate-reducing, filter layer below drainfield; material reacts with nitrate

• Rules became effective July 31, 2018

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Aerobic Treatment Unit (ATU)

Permitting Category“A sewage treatment unit which introduces air into sewage to provide biochemical stabilization within a treatment receptacle”, Rule 64E-6.002(2).

Three main types of treatment technologies:

• Extended Aeration – Air bubbled through water• Fixed Media Filters - Water sprinkled through air or loose filter material

• Combined - Extended aeration and fixed media

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Aerobic Treatment Unit

About 8,000 NSF 40 units installed in Florida

Aeration Tank

Sewage Pretreatment Tank or

CompartmentDrainfield

Presenter

Presentation Notes

NSF/ANSI 40 is a residential septic system standard. Systems certified as NFS 40 meet minimum effluent quality standards for CBOD5, TSS, and pH CBOD5: Carbonaceous Biochemical Oxygen Demand (5day) Carbonaceous biochemical oxygen demand or CBOD is a method defined test measured by the depletion of dissolved oxygen by biological organisms in a body of water in which the contribution from nitrogenous bacteria has been suppressed. CBOD is a method defined parameter is widely used as an indication of the pollutant removal from wastewater. TSS: Total suspended solids (TSS) are a water quality parameter that is defined as the quantity of material suspended in a known volume of water that is trappable in a filter.

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Aerobic Treatment UnitCertification to meet NSF/ANSI Standard 40

“Typical” Septic Tank Effluent

NSF 40 Standard for 30-day Average

CBOD5

Carbonaceous Biochemical Oxygen

Demand

216 mg/L 25 mg/L

TSS (total suspended solids)

61 mg/L 30 mg/L

Microbe Reduction loaded 99.9% (not part of standard but typical,

not disinfection)

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Certified to meet NSF/ANSI Standards 40 and 245 (50% Nitrogen Reduction)

Newer: Nitrogen-Reducing ATU

Aeration Chamber

Recycle for more denitrification

SewageDrainfield

Presenter

Presentation Notes

Standards 40 and 245??? Should I remove? * No, this is an important point. The NSF 245 standard when combined with NSF 40 (required) achieves at least a 50% reduction in nitrogen. The importance is that using an approved 40/245 system as part of a performance based system can make it easier to obtain the required 65% nitrogen reduction for the Springs areas. (DOH already has a list of these approved systems in Florida). * Official definition: NSF/ANSI 245 defines total nitrogen reduction requirements to meet the growing demand for nutrient reduction in coastal areas and sensitive environments. NSF/ANSI 245 covers residential wastewater treatment systems with rated capacities between 400 and 1,500 gallons (1,514 and 5,678 liters) per day.

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Aerobic Treatment Units

Advantages Additional requirements

Much higher treatment(greater reduction in BOD

and TSS) Can extend drainfield life Reduced drainfield size Replacement system inareas with chronic failing

septic tanks

Operating expense Most require electricity

More frequent routine maintenance Subject to upsets under heavy loads

Less resilient to long periods of no use (starvation)Operating permit with annual inspection by CHD required

Maintenance Contract required

Presenter

Presentation Notes

All ATUs meet the NSF 40 standard but not all meet the NSF 245 as well.

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•Permitting Category•Specialized onsite sewage treatment and disposal system•In many cases, includes an ATU•Designed to achieve specific and measurable established performance standards for: Carbonaceous biochemical oxygen demand (CBOD5), total suspended solids (TSS),TN (total nitrogen), TP (total phosphorus), and Fecal coliforms

Performance-Based Treatment Systems (PBTS)

Presenter

Presentation Notes

As noted earlier, a PBTS that uses an NSF 40/245 approved system starts with at least a 50 % reduction and many of them have tested at 65% or more making them an easier “off-the shelf way to meet the Springs standard of 65% reduction in Florida.

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Designed by an engineerPerformance standards can range from baseline (=septic system) to some advanced level including nutrient reduction and disinfectionIncentives for better standards:

Increased lot flows, setback reductions, drainfield size reductionsRequires Operating PermitsMaintenance ContractMonitoring and SamplingCHD Inspection - Annually

Performance-Based Treatment Systems

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Spring Basin Management Action Plan (BMAP) and Priority Focus Areas

BMAP= Basin Management Action Plan for Impaired Waters

Presenter

Presentation Notes

Charlotte County is not in a BMAP that has an outstanding Florida Springs. The Springs and Aquifer Protection Act (passed in 2016) does not apply to Charlotte County. For the Act, there are priority focus areas (areas of vulnerability near the outstanding springs) where nitrogen-reducing systems are required if there is no sewer connection for new construction (and eventually repairs/modifications)

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Nitrogen-Reducing Treatment System OptionsOverall Goal of Nitrogen Removal: ≥65%

•Certified to meet National Sanitation Foundation (NSF) Standards 40 and 245

•Require operating permit (OP), maintenance entity (ME) and maintenance contract agreement (MCA)

Nitrogen-reducingAerobic Treatment

Units

• Must be designed by Florida Professional Engineer

• Require OP, ME and MCAPerformance-based Treatment Systems

• No engineer design should be needed unless lot conditions require

• No OP, ME or MCA needed

In-ground Nitrogen-Reducing Biofilter

(INRB) stacked under a conventional drainfield

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Don't flush cigarette butts, tampons, condoms or other indigestible materials down the toilets or sinks. These will clog the outlet filter or drain field.

Don't pour grease down the drain -- grease cannot be digested by the septic system and will clog it! Instead, pour the grease into an empty can or bottle and discard with the trash.

Don't use excessive amounts of bleach or other cleaning products -- too much will interfere with the bacterial action inside the septic tank. Small amounts of household bleach or laundry detergent can be used without ill effects.

Don't do several loads of laundry back-to-back -- instead, space your wash loads out over the week so that the septic system does not have to process so much water (a typical wash load uses between 60 -90 gallons per load!).

Don't plant trees or shrubbery near or over your drainfield. Roots from trees and plants will grow into the drainlines and clog them.

Don't allow vehicles to drive over any part of your septic system. Traffic over your drainfield can crush the pipes or pack down the soil around them, and driving over the septic tank can cause the tank's lid to crack or break apart!

Septic System Care

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Do conserve water -- the less water you use, the less wastewater your septic system will have to process! Look into installing water-conserving showerheads, toilets or other water-saving features.

Do have your septic tank pumped out periodically. The Florida Department of Health recommends that septic tanks be pumped out every four to five years to reduce accumulations of sludge in the tank.

Do check your plumbing for leaks on a regular basis. A leaking toilet flapper valve can let hundreds of gallons of wasted water into your septic system, causing stoppages and overloaded drainfields.

Do consult your local health department for more information. Our Environmental Health Professionals can provide you with many tips and information to help your septic system last as long as possible.

What you can do to help…

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Bureau of Environmental HealthDivision of Disease Control and Health Protection

Florida Department of Health

Florida Department of Health in Charlotte County

For more information:

overview of septic systems - charlotte county, florida · 2019-01-31 · septic system will have to...

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